if you can buy four bunches of purple grapes for 10$
Cost of the four bunches = $10
then with the help of $10 we get 4 bunches
with the help of one dollar we get = 4/10 bunches
For 25$, multiply 15 by the number of bunches in$1
With the $25, we can buy 10 bunhces
Answer : 10 bunches